[PATCH 2/3] iscsi-target: Fix connection reset hang with percpu_ida_alloc

["Nicholas A. Bellinger" <nab@daterainc.com>]

From: Nicholas Bellinger <nab@linux-iscsi.org>

This patch addresses a bug where connection reset would hang
indefinately when percpu_ida_alloc() was starved for tags,
and always assumed uninterruptible sleep mode.

So now with percpu_ida_alloc_state() available to make
interruptible sleep optional, convert iscsit_allocate_cmd()
to set TASK_INTERRUPTIBLE when GFP_KERNEL is passed, or
set TASK_RUNNING when GFP_ATOMIC is passed.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target_util.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 0819e68..6cf1d95 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -156,9 +156,13 @@ struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
 {
 	struct iscsi_cmd *cmd;
 	struct se_session *se_sess = conn->sess->se_sess;
-	int size, tag;
+	int size, tag, state = (gfp_mask & __GFP_WAIT) ? TASK_INTERRUPTIBLE :
+				TASK_RUNNING;
+
+	tag = percpu_ida_alloc_state(&se_sess->sess_tag_pool, state);
+	if (tag < 0)
+		return NULL;
 
-	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, gfp_mask);
 	size = sizeof(struct iscsi_cmd) + conn->conn_transport->priv_size;
 	cmd = (struct iscsi_cmd *)(se_sess->sess_cmd_map + (tag * size));
 	memset(cmd, 0, size);
-- 
1.7.10.4